1Field of the Invention
The present invention is directed to an expansion joint system for bridges, roadways, parking structures and the like wherein adjacent roadway slabs are subject to movement yet a flexible seal is required in the gap between adjacent slabs.
2. Prior Art
Roadways, bridges and parking structures are customarily built of sections or slabs arranged with an expansion gap between adjacent slabs. It is known that the slabs will expand and contract in response to temperature changes. In many applications, such as bridges and parking structures, loading due to vehicular traffic also causes vertical movement of the slabs.
Notwithstanding the movement of the slabs, a flexible joint which will retain a water tight seal is highly desirable. A water tight seal will prevent water from getting beneath the slabs and rusting bridges or parking structure components. In freezing conditions, the water will cause damage because of heaving. Additionally, road salts are highly corrosive to bridges. A seal in the expansion joint will also prevent debris from lodging in the joint and causing problems.
Many materials in various arrangements have heretofore been used to seal roadway, bridge and parking structure expansion joints. Some of the materials lose their adhesion and quickly require replacement. In applications with an asphalt overlay, the seal might hold but the asphalt may crumble away.
In new roadway, bridge and parking structure construction, time may not be a critical factor in installation of the joint seal. In remedial applications, however, time is a critical factor so that down time is minimized particularly, where vehicular traffic has to be returned before all of the components have cured.
Various expansion joints have heretofore been proposed. As an example, Gibbon (U.S. Pat. No. 4,699,540) discloses an expansion joint system where a preformed longitudinal resilient tube of heat cured silicone is installed in the recess. An initially flowable adhesive silicone is then injected into the recess on both sides of the tube.
Galbreath (U.S. Pat. No. 4,447,172) discloses a flexible elastomeric membrane wherein adhesive may be utilized to assist in holding the membrane to the side rails.
Cihal (U.S. Pat. No. 4,963,056) provides layers of plastic concrete compound which are cast in the recess. An adhesive coating of an epoxy resin is coated on top of the second layer to assist in retaining a pad which spans the gap.
Belangie (U.S. Pat. No. 4,824,283 and 4,927,291) provides a preformed strip of silicone which floats or is embedded in a silicone adhesive.
Peterson et al. (U.S. Pat. No. 4,279,533) discloses an expansion joint system wherein a metal plate secured to one concrete section bridges the expansion slot. The remainder of the recess is filled with a premolded elastomeric slab surrounded by edge portions which are molded on the job site.
Watson (U.S. Pat. No. 4,080,086) discloses a joint sealing apparatus having a pair of elongated elastomeric pads embedded with crushed rock which are secured to the concrete slabs by studs and nuts. A flexible resilient elongated member extends between the pads.
Accordingly, it is a principal object and purpose of the present invention to provide an expansion joint system for both new construction and remedial applications which may be installed quickly yet is extremely durable.
It is a further object and purpose of the present invention to provide an expansion joint system which combines a capability of adhering to both concrete and steel as well as acting as a primer for adhesion to a silicone sealant.